Auto-synchronizing gear system

ABSTRACT

A transmission system is shown having shafts meshing cyclical members with respective teeth and tooth-spaces respectively arranged in combinational code groups which will only mesh when said members are in predetermined relative orientation.

ited States Patent [191 Cozzy et al.

[451 Ang.. is, i973 [54] AUTO-SYNCl-IRONIZING GEAR SYSTEM [75] Inventors: Thomas William Cozzy, Burlington; Robert Pettinga, Shelburne, both of [73] Assignee: General Electric Company,

Burlington, Vt.

[22] Filed: Apr. 5, 1971 [2l] Appl. No.: 130,994

[52] U.S. Cl. 89/13 R, 74/243 R, 74/437 [5l] Int. Cl. F16h 55/08, Fih 55/30, F41d 9/06 [58] Field of Search 74/434, 435, 436, 74/437, 243 R; 89/12, 13, 33 MC, 126, 160,

[56] References Cited UNITED STATES PATENTS 73,943 2/1868 Allen 74/437 465,141 12/1891 McCray 74/243 R 3,029,654 4/1962 Hill 74/243 R 1,201,748 7/1915 Luce 74/243 R 1,432,494 i0/ 1922 Regen 74/435' 562,846 6/1896 Neils 89/13 R Primary Examiner-Stephen C. Bentley Attorney-Bailin Kuch, H. C. Burgess, l. M. Freedman, Frank L. Neuhauser, Oscar B. Waddell and Joseph B. Forman [57] STRACT A transmission system is shown having shafts meshing cyclical members with respective teeth and toothspaces respectively arranged in combinational code groups which will only mesh when said members are in predetermined relative orientation.

l2 Claims, 9 Drawing Figur Patented Aug. 14, 1973 3 Sheets-Sheet s 0 A @TMW 1 M 4 r E@ om# wim@ Q OUD H H NUDE Patented Aug. 14, 1973 3 Sheets-Sheet 3 INVENTORS @56er /%/7'//y69 BY COZZ),

AUTO-SYNCHRONIZING GEAR SYSTEM BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to the synchronization of cyclical members, for example, shafts, which are coupled by digital devices, for example, gears, and timing sprockets and chains.

2. Description of the Prior Art It is frequently necessary to synchronize the relative angular orientation of two cyclical members, such as the main rotor R in a Gatling type gun and the ammunition sprocket shaft S in its feeder. Conventionally this is done by visually aligning timing marks, or by the use of detent pins or buttons to mechanically align the shaft or some coupled thereto member with a fixed reference such as a stationary housing. Shafts which must, of necessity, be timed, are shown in U.S. Pat. Nos. 2,959,106; 2,965,004; 2,971,440; and 2,993,415.

Accordingly, it is an object of this invention to provide a system for the autosynchronization of such shafts, replacing visual timing marks and timing buttons, pins, and related machining operations, thereby eliminating the possibility of human error during assembly and reassembly of the equipment.

SUMMARY OF THE INVENTION A feature of this invention is the provision of shafts having meshing cyclical members with respective projections and lacunae respectively arranged in combinational code groups which will only mesh when said members are in predetermined relative orientations.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features and advantages will be apparent from the following specification taken in conjunction with the accompanying drawing in which:

FIG. l is a right side view of a typical two-layer gear embodying this invention;

FIG. 2 is a left side view of the gear of FIG. l;

FIG. 3 is a diametral cross-sectional view of the gear of FIG. l;

FIG. 4 is a plan schematic of the tooth arrangement of the gear of FIG. 3;

FIG. 5 is a plan schematic of another tooth arrangement adapted to mesh with the gear of FIG. l;

FIG. 6 is a plan view of a two-layer timing chain embodying this invention;

FIG. 7 is a cross-sectional view of thechain of FIG. 6taken along the plan VII-VII;

FIG. 8 is a cross-sectional view of the chain of FIG. 6 taken along the plane VIII-VIII; and

FIG. 9 is a perspective view of a Gatling type gun utilizing the embodiment of FIG. l.

DESCRIPTION OF THE FIRST EMBODIMENT A pair of two-layer, involute, gears is illustrated in FIGS. l through 5. One gear l0 comprises a hub l2 on which is formed a first annulus I4 of teeth and a second annulus 16 of teeth, the two annuli being here shown as directly in phase, with their respective nominal, alternating single tooth and single tooth-space positions disposed in longitudinal rows. The teeth of each of the annuli are respectively arranged in a code pattern of unitary teeth, unitary spaces, plural teeth and plural spaces. The patterns of mating annuli on respectively mating gears are adapted to mutually interfit in at least one orientation within 360, if only one mutual orientation is acceptable; or in fractions of 360, if more than one orientation is permissible.

The conventional uniformly toothed pair of gears provides the limit of the invention. For example, a 36- toothed gear can mesh with a 36toothed gear at any of 36 different orientations. Each tooth provides both a mesh-orientation function and a power-transmission function.

To preclude intermeshing at any particular orientation which would otherwise be feasible with unitary teeth it is necessary to provide a double tooth, i.e., a tooth whose top land extends between two normally adjacent teeth positions without an intermediate tooth space. v

The mating gear 20 is shown in FIG. 5 to have two annuli 22, 24 to respectively mesh with the two annuli 14, 16 of the gear l0 in any one of four possible orientationsjThe gears may be oriented and fixed to their respective shafts by any suitable means such as diametral holes 50 and respective pins, not shown.

The minimum number of adjacent tooth positions which will admit or preclude intermeshing at any particular orientation of the gears of a particular set of gears is determined by the no mesh angle for such a set. This no mesh angle is approximated by the angle subtended by the two points of intersection of the respective outside circles of the gears of the set. For a gear having N tooth positions, the no mesh angle" approximates 2 (cos-l N/(Nl-2)) -l- (360/N) In the gear set-shown in the drawing, wherein the gears have I8 and 36 tooth positions respectively, the no mesh angle subtends approximately 3.55 tooth positions. Thus, when setting up the combination code, four adjacent tooth positions must be considered concurrently.

To insure the power transmission function, at least one tooth position in each longitudinal row across the several annuli on a gear should have a functioning leading tooth face and flank to bear against a functioning trailing tooth face and flank on the mating gear. The respective tooth faces and flanks may be on either a single or a double tooth;

While the` embodiment shown in FIGS. 4 and 5 has its tooth positions in its several annuli in phase, that is, in longitudinal rows; the tooth positions inthe several annuli may be out of phase so long as there are tooth faces and flanks available to transmit power between the gears.

More than two annuli may be provided on each gear if more tooth positions are required in each row to meet the needs of precluding meshing, Vyet providing power transmission.

A two-layer timing chain 30 is illustrated in FIGS. 6, 7 and 8, but it will be appreciated that as many layers or strands may be combined as is necessary to mesh with respective annuli of teeth on sprocket wheels 32, 34. The links are of two types, a conventional link 42 with a central opening to accommodate a tooth of a sprocket wheel, and a link without an opening, and which thus will not accommodate a tooth. The conventional, or open, link may be fully conventional, with link plates, pins, bushings and rollers. The link 44 without an opening, or closed link, is here shown as a solid element, but may be a modified conventional link with link plates, pins, bushings and rollers, and an additional central means, such as a pin between the link plates, to

bar thc entrance of a tooth into the opening. The open and closed links and teeth and missing teeth are arranged in a combinational code to determine the mesh orientation.

We claim: 1. A power transmission system, comprising: two shafts, an orientation device including: two meshing cyclical members intercoupling said shafts, each of said members having a plurality of projections and lacunae respectively arranged in at least two non-identical annular rows of combinational code groups which will only mesh when said members are in predetermined relative orientation wherein the projections on one of said members adjacent said other one of said members are accommodated by respective lacunae on said other one of said members, each of said members comprising a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces. 2. A system according to claim ll wherein: each of said annular rows of projections is regularly divided into a plurality of nominal, alternating, single tooth and single tooth-space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in each of said other annular rows to define a longitudinal row of tooth positions, there being at least one functioning, leading tooth face and flank and at least one functioning trailing tooth face and flank in each of said longitudinal rows. 3. A machine gun comprising: a rotor having a first cyclical member; and a feeder having a second cyclical member meshed with said first cyclical member; each of said members having a plurality of projections and lacunae respectively arranged in at least two non-identical rows of combinational code groups which will only mesh when said members are in predetermined relative orientation wherein the projections on one of said members adjacent said other one of said members are accommodated by respective lacunae on said other one of said members; each of said members comprising a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces. 4. A gun according to claim 3 wherein each of said annular rows of teeth is regularly divided into a plurality of nominal, alternating, single tooth and single tooth and single tooth-space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in each of said other annular rows to define a longitudinal row of tooth positions, there being at least one functioning, leading tooth face and flank and at least one functioning trailing tooth and flank in each of said longitudinal rows. 5. A power transmission system, comprising: two shafts, an orientation device including:

two cyclical members intercoupling said shafts and mutually meshing along a path; each of said members having a plurality of projections and a plurality of lacunae, each lacuna being disposed between two immediately adjacent projections, each projection and lacuna having a respective effective dimension along said path, said plurality of projections including at least a first sub plurality and a second sub plurality of projections, said projections of said first sub plurality each having a first respective effective dimension along said path in common, said projections of said second sub plurality each having a second respective effective dimension along said path in common and different from said first dimension of said projections of said first plurality, said plurality of lacunae including at least a first and a second sub plurality of lacunae, said lacunae of said first sub plurality each having a first respective effective dimension along said path in common, said lacunae of said second sub plurality each having a second respective effective dimension along said path in common and different from said first dimension of said lacunae of said second plurality, said plurality of projections and lacunae of each of said members being respectively arranged in at least two non-identical annular rows of combinational code groups wherein said members will only mesh when they are in predetermined relative orientation with those projections on each of said members adjacent the other of said members being accommodated by respective lacunae on said other of said members. 6. A system according to claim 5 wherein: each of said members comprises a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces. 7. A system according to claim 5 wherein: each of said annular rows of projections is regularly divided into a plurality of nominal, alternating, single tooth and single tooth-space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in each of said other annular rows to define a longitudinal row of tooth positions, there being at least one functioning leading tooth face and flank and at least one functioning trailing tooth face and flank in each of said longitudinal rows. 8. A machine gun comprising: a rotor having a first cyclical member; a feeder having a second cyclical member;

said two cyclical members mutually meshing along a path; each of said members having a plurality of projections and a plurality of lacunae, each lacuna being disposed between two immediately adjacent projections, each projection and lacuna having a respective effective dimension along said path,

said plurality of projections including at least a first sub plurality of projections,

.said projections of said first sub plurality each having a first respective effective dimension along said path in common,

said projectionsot` said second sub plurality each having a second respective effective dimension along said path in common and different from said-first dimension of said projections of said first plurality,

said plurality of lacunae including at least a first and a second sub plurality of lacunae,

' said lacunae of said tirst sub plurality each having a first respective effective dimension along said path in common,

said lacunae of said second sub plurality each having a second respective effective dimension along said path in common and different from said rst dimension of said lacunae of said second plurality,

said plurality of projections and lacunae of each of said members being respectively arranged in at least two non-identical annular rows of combinational code groups wherein said members will only mesh when they are in-predetermined relative orientation with those projections on each of said members adjacent the other of said members being accommodated by respective lacunae on said other of said members. 9. A gun according to claim 8 wherein each of said members comprises a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces. 10. A gun according to claim 9 wherein: each of said annular rows of teeth is regularly divided into a plurality of nominal, alternating, single tooth and single tooth-'space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in `each of said other annular rows to define a longitudinairow of tooth positions,

'soi

there being at least one functioning, leading tooth face and flank and at least one functioning trailing tooth face and flank in each of said longitudi nal rows. 1li. A power transmission system comprising: two shafts; an orientation device including:

an endless chain having a strand of links,

said links of said strand consisting of a tirst plurality oi links each having a central space for receiving a sprocket tooth, and a second plurality of links each having a central obstruction for blocking a sprocket tooth, said first andsecond pluraiities of links in said strand being arranged in a combination code; and a sprocket having a layer,

said layer having a first plurality of tooth positions spaced apart at a uniform pitch angle, a second plurality of said tooth positions being occupied respectively by teeth, and the remainder of said tooth positions being cooupied by tooth omissions, at least two adjacent tooth positions of said first plurality being occupied by teeth, said second plurality of tooth positions and said remainder of tooth positions being arranged in a matching combination code with said strand of links; whereby said chain and said sprocket will only mesh when they are in a predetermined relative orientation wherein the teeth on said sprocket adjacent said chain are accommodated by rcspective links in said chain. i2. A system according to claim il wherein: said `chain has a plurality of strands of links, and at least two of said plurality of strands of links have non-identical combination codes; and said sprocket has a like plurality of layers of tooth positions, each such layer matching a respective strand o links.

#entre 

1. A power transmission system, comprising: two shafts, an orientation device including: two meshing cyclical members intercoupling said shafts, each of said members having a plurality of projections and lacunae respectively arrangeD in at least two non-identical annular rows of combinational code groups which will only mesh when said members are in predetermined relative orientation wherein the projections on one of said members adjacent said other one of said members are accommodated by respective lacunae on said other one of said members, each of said members comprising a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces.
 2. A system according to claim 1 wherein: each of said annular rows of projections is regularly divided into a plurality of nominal, alternating, single tooth and single tooth-space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in each of said other annular rows to define a longitudinal row of tooth positions, there being at least one functioning, leading tooth face and flank and at least one functioning trailing tooth face and flank in each of said longitudinal rows.
 3. A machine gun comprising: a rotor having a first cyclical member; and a feeder having a second cyclical member meshed with said first cyclical member; each of said members having a plurality of projections and lacunae respectively arranged in at least two non-identical rows of combinational code groups which will only mesh when said members are in predetermined relative orientation wherein the projections on one of said members adjacent said other one of said members are accommodated by respective lacunae on said other one of said members; each of said members comprising a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces.
 4. A gun according to claim 3 wherein each of said annular rows of teeth is regularly divided into a plurality of nominal, alternating, single tooth and single tooth and single tooth-space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in each of said other annular rows to define a longitudinal row of tooth positions, there being at least one functioning, leading tooth face and flank and at least one functioning trailing tooth and flank in each of said longitudinal rows.
 5. A power transmission system, comprising: two shafts, an orientation device including: two cyclical members intercoupling said shafts and mutually meshing along a path; each of said members having a plurality of projections and a plurality of lacunae, each lacuna being disposed between two immediately adjacent projections, each projection and lacuna having a respective effective dimension along said path, said plurality of projections including at least a first sub plurality and a second sub plurality of projections, said projections of said first sub plurality each having a first respective effective dimension along said path in common, said projections of said second sub plurality each having a second respective effective dimension along said path in common and different from said first dimension of said projections of said first plurality, said plurality of lacunae including at least a first and a second sub plurality of lacunae, said lacunae of said first sub plurality each having a first respective effective dimension along said path in common, said lacunae of said second sub plurality each having a second respective effective dimension along said path in common and different from said first dimension of said lacunae of said second plurality, said plurality of projections and lacunae of each of said members being respectively arranged in at least two non-identical annular rows of combinational code groups wherein said members will only mesh when they are in predetermined relative orientation with those projections on each of said members adjacent the other of said members being accommodated by respective Lacunae on said other of said members.
 6. A system according to claim 5 wherein: each of said members comprises a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces.
 7. A system according to claim 5 wherein: each of said annular rows of projections is regularly divided into a plurality of nominal, alternating, single tooth and single tooth-space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in each of said other annular rows to define a longitudinal row of tooth positions, there being at least one functioning leading tooth face and flank and at least one functioning trailing tooth face and flank in each of said longitudinal rows.
 8. A machine gun comprising: a rotor having a first cyclical member; a feeder having a second cyclical member; said two cyclical members mutually meshing along a path; each of said members having a plurality of projections and a plurality of lacunae, each lacuna being disposed between two immediately adjacent projections, each projection and lacuna having a respective effective dimension along said path, said plurality of projections including at least a first sub plurality of projections, said projections of said first sub plurality each having a first respective effective dimension along said path in common, said projections of said second sub plurality each having a second respective effective dimension along said path in common and different from said first dimension of said projections of said first plurality, said plurality of lacunae including at least a first and a second sub plurality of lacunae, said lacunae of said first sub plurality each having a first respective effective dimension along said path in common, said lacunae of said second sub plurality each having a second respective effective dimension along said path in common and different from said first dimension of said lacunae of said second plurality, said plurality of projections and lacunae of each of said members being respectively arranged in at least two non-identical annular rows of combinational code groups wherein said members will only mesh when they are in predetermined relative orientation with those projections on each of said members adjacent the other of said members being accommodated by respective lacunae on said other of said members.
 9. A gun according to claim 8 wherein each of said members comprises a gear, with said projections and lacunae defined by single and double teeth and single and double tooth spaces.
 10. A gun according to claim 9 wherein: each of said annular rows of teeth is regularly divided into a plurality of nominal, alternating, single tooth and single tooth-space positions, each of said tooth positions in one of said annular rows having a predetermined phase relationship with an adjacent tooth position in each of said other annular rows to define a longitudinal row of tooth positions, there being at least one functioning, leading tooth face and flank and at least one functioning trailing tooth face and flank in each of said longitudinal rows.
 11. A power transmission system comprising: two shafts; an orientation device including: an endless chain having a strand of links, said links of said strand consisting of a first plurality of links each having a central space for receiving a sprocket tooth, and a second plurality of links each having a central obstruction for blocking a sprocket tooth, said first and second pluralities of links in said strand being arranged in a combination code; and a sprocket having a layer, said layer having a first plurality of tooth positions spaced apart at a uniform pitch angle, a second plurality of said tooth positions being occupied respectively by teeth, and the remainder of said tooth positions being coOupied by tooth omissions, at least two adjacent tooth positions of said first plurality being occupied by teeth, said second plurality of tooth positions and said remainder of tooth positions being arranged in a matching combination code with said strand of links; whereby said chain and said sprocket will only mesh when they are in a predetermined relative orientation wherein the teeth on said sprocket adjacent said chain are accommodated by respective links in said chain.
 12. A system according to claim 11 wherein: said chain has a plurality of strands of links, and at least two of said plurality of strands of links have non-identical combination codes; and said sprocket has a like plurality of layers of tooth positions, each such layer matching a respective strand of links. 